How to change ac3 from 23 to 29 fps, ntsc?

[Lolena1888]

I tried with Besweet, but afterconverting I can not open ac3 file, there's something wrong. Which other programs can help me?

[adam]

What exactly are you trying to do?

The NTSC standard actually only supports a playback rate of 29.97fps. 23.976fps sources are telecined in real time to 29.97fps by creating new fields/frames from existing ones. The result is that the runtime stays the same despite the increase in fps.

What I'm saying is that essentially, there is no difference in the audio between a 23.976fps source and a 29.97fps source. If you took a 23.976fps source and converted it, properly, to 29.97fps you could just leave the audio as is and it would remain in sync.

If you truly wanted to speedup your audio from 23.976fps to 29.97fps then you'd have to be mixing an Alvin and the Chipmunks record, because that's what it will sound like with the huge change in pitch. You can always offset this but then it will sound like Satan.

[reboot]

Audio doesn't have a framerate!!!
Besweet is totally misleading, and impossible to use.
You don't need to change the audio, you simply author your encoded video with the original ac3.
If you didn't change the running time of the video, then the audio will be in sync.

[Lolena1888]

The problem is that I want to authorize dvd with 2 audio streams in different languages.

I have 1 m2v file -29,970, 1 ac3 file - 29,970 and 1 ac3 file - 23,976. I want to sync them in ulead media studio pro, because they are different length.

Do your words mean that I have to sync just start of the movie and ac3 file_23 and everything will be OK?

[SLK001]

Don't do anything to your audio. Irregardless of your framerate, your audio stays the same. Like reboot says, audio doesn't have a framerate.

Or, just to satisfy your thinking, apply a pulldown the the 23.976fps file, then all your audio will be 29.97 "fps".

[Cornucopia]

If movie1 had video = 10min. M2V @ 29.97 Frames Per second, with
audio1 = 10min. AC3 @ 48000 Samples Per second, and you had a
audio2 = 12min. AC3 @ 48000??? Samples Per second (from somewhere else), and you wanted

to make audio 2 fit in sync with audio1 and the video, then
convert the AC3 to WAV @48000, then open in audio editor to stretch/shrink, otherwise known as TimeCompression/Expansion.
get it to 10min. Save as new WAV @48000.
Compress back to new AC3 @48000

Author(ize) that.

If that's not what you're talking about, I don't know how to help unless you give MUCH more info.

Scott

[Lolena1888]

Thanks for all replies. Very much helpful.

To Cornucopia.
That was exactly what I wanted.

Thank you all, guys. Very helpful for understanding the process.

[generaljoy]

AC3 is a pain. Always make it into a WAV. Way easier to work with even if it's a little bigger.

[SLK001]

AC3 is a pain. Always make it into a WAV. Way easier to work with even if it's a little bigger.

A little bigger? Try more than 7 times the size. Yes, it is a pain, but you can pick up more than 1 GByte of space by using .AC3 over .WAV audio. One hour of 16 bit, 2 channel, 48kbps audio consumes about 700 MByte of space - the same .AC3 is only about 100 MBytes.

[Hyper Shinchan]

AC3 is a pain. Always make it into a WAV. Way easier to work with even if it's a little bigger.

.
WAV (uncompressed PCM) is a waste of space.

[jyn999]

I tried with Besweet, but afterconverting I can not open ac3 file, there's something wrong. Which other programs can help me?

I have used BeSweetGUI to convert audio files from 23.976FPS to 29.976FPS. Select the "presets" box and highlight the desired frame conversion rate in the drop-down list to the right of the "presets" box.

[Lolena1888]

I did it from the very beginning. After convertion I couldn't open this new file. GSPOT showed some error in codecs.

[Lolena1888]

The problem is the same. File 23.96 has length 1:40 min, file 29.96 - 1:36. Compilation in dvd lab gives an error. I wanted to cut the first file, but they start and and with the same scenes. So I don't know how to sync them and compile

[Hyper Shinchan]

When I convert from 23 to 25 fps the audio is really a garbage, it plays slowly, for this reason I prefer to mantain the original video and audio settings.